A
B
C
D
Explanation
Correct answer: A.
Choice A is correct. Taking the square root of both sides of yields . Subtracting from both sides of this equation yields . Therefore, this equation has exactly one distinct real solution.
Desmos solution:
Note: d(r) is the discriminant of (x+15)^2=r; d(0)=0 means choice A has exactly one real solution.
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice B
Choice B is incorrect. This equation has no distinct real solutions, not exactly one distinct real solution.
Choice C
Choice C is incorrect. This equation has exactly two distinct real solutions, not exactly one distinct real solution.
Choice D
Choice D is incorrect. This equation has exactly two distinct real solutions, not exactly one distinct real solution.